at the time which accounted for locating facilities by these water bodies.
There are numerous chemicals that can be described “toxic” which may cause health effects in individuals in different settings and at exposure levels that are routinely allowed for release to the environment in lower concentrations under state and federal agency permits. Even if the potential hazard of environmental contamination could have been anticipated, the types of analyses that are necessary to understand the risk to the environment would require consideration of concentrations in the recycled pulp and effluent, along with environmental sampling or fate-and-transport modeling. These types of assessments had not been conducted and were not routinely being considered in the 1960s.
Dr.
Kittrell above and in many instances in his report many instances loosely describes NCRs knowledge that “PCBs” were “toxic”. Routinely both Dr. Rodricks and Dr. Kittrell lump all Aroclors under the one term, PCBs, when the focus in this matter should be on Aroclor 1242 and its differential toxicity and the evolving scientific information available over time for this product. Although there were well-known hazards associated with some PCBs in occupational settings, NCR’s investigations of possible toxicity of its CCP containing Aroclor 1242 (the Hill Top studies) had shown low to negligible toxicity, especially at lower concentrations. As described in my earlier reports, NCR had no scientifically credible reason to conclude that the potential toxicity of CCP and its components would likely result in risks at environmental levels of exposure.
Similarly, when stating that NCR knew that PCBs were “stable”, this relative term is generally true for some PCBs in many applications but not necessarily in environmental settings. In my earlier reports, I describe how from the time Jensen presented his findings through the 1960s and into the early 1970s, numerous researchers collected and analyzed environmental samples – they identified higher chlorinated Aroclors (or European equivalent higher chlorinated commercial PCB mixtures), not the lower chlorinated mixtures as were used by
NCR.
By the early 1970s scientific evidence for the potential impact of certain types PCBs on wildlife and the environment was accumulating but far from mature. As noted above, in 1972, the year after NCR had stopped use of PCBs, the Interagency Task Force on PCBs stated there was: